diff --git a/aoc2019/benches/bench.rs b/aoc2019/benches/bench.rs
index 46cac6a..6a37c10 100644
--- a/aoc2019/benches/bench.rs
+++ b/aoc2019/benches/bench.rs
@@ -8,6 +8,7 @@ use aoc2019::day05;
 use aoc2019::day06;
 use aoc2019::day07;
 use aoc2019::day08;
+use aoc2019::day09;
 
 fn aoc2019_all(c: &mut Criterion) {
     c.bench_function("day01", |b| b.iter(|| day01::run().unwrap()));
@@ -18,6 +19,7 @@ fn aoc2019_all(c: &mut Criterion) {
     c.bench_function("day06", |b| b.iter(|| day06::run().unwrap()));
     c.bench_function("day07", |b| b.iter(|| day07::run().unwrap()));
     c.bench_function("day08", |b| b.iter(|| day08::run().unwrap()));
+    c.bench_function("day09", |b| b.iter(|| day09::run().unwrap()));
 }
 
 criterion_group! {
diff --git a/aoc2019/input/day09.txt b/aoc2019/input/day09.txt
new file mode 100644
index 0000000..9a91828
--- /dev/null
+++ b/aoc2019/input/day09.txt
@@ -0,0 +1 @@
+1102,34463338,34463338,63,1007,63,34463338,63,1005,63,53,1102,1,3,1000,109,988,209,12,9,1000,209,6,209,3,203,0,1008,1000,1,63,1005,63,65,1008,1000,2,63,1005,63,904,1008,1000,0,63,1005,63,58,4,25,104,0,99,4,0,104,0,99,4,17,104,0,99,0,0,1102,533,1,1024,1102,260,1,1023,1101,33,0,1016,1102,37,1,1017,1102,1,36,1009,1101,0,35,1011,1101,0,27,1004,1101,0,0,1020,1101,242,0,1029,1101,0,31,1018,1101,0,38,1007,1101,0,29,1015,1102,1,23,1006,1101,25,0,1002,1102,1,39,1008,1101,0,20,1001,1102,1,34,1012,1102,370,1,1027,1101,30,0,1010,1102,24,1,1014,1101,21,0,1000,1101,22,0,1003,1102,1,26,1005,1101,0,267,1022,1101,1,0,1021,1101,28,0,1013,1101,0,32,1019,1101,251,0,1028,1101,377,0,1026,1102,1,524,1025,109,4,2102,1,-4,63,1008,63,21,63,1005,63,203,4,187,1105,1,207,1001,64,1,64,1002,64,2,64,109,6,1201,-1,0,63,1008,63,36,63,1005,63,229,4,213,1105,1,233,1001,64,1,64,1002,64,2,64,109,18,2106,0,0,4,239,1001,64,1,64,1106,0,251,1002,64,2,64,109,-4,2105,1,-1,1001,64,1,64,1105,1,269,4,257,1002,64,2,64,109,-6,1205,3,287,4,275,1001,64,1,64,1106,0,287,1002,64,2,64,109,-19,1202,9,1,63,1008,63,41,63,1005,63,307,1105,1,313,4,293,1001,64,1,64,1002,64,2,64,109,8,2108,23,-1,63,1005,63,331,4,319,1106,0,335,1001,64,1,64,1002,64,2,64,109,-3,21101,40,0,10,1008,1014,40,63,1005,63,361,4,341,1001,64,1,64,1106,0,361,1002,64,2,64,109,28,2106,0,-5,1001,64,1,64,1106,0,379,4,367,1002,64,2,64,109,-30,1208,7,36,63,1005,63,401,4,385,1001,64,1,64,1105,1,401,1002,64,2,64,109,-1,2101,0,6,63,1008,63,38,63,1005,63,427,4,407,1001,64,1,64,1105,1,427,1002,64,2,64,109,7,1207,-3,27,63,1005,63,445,4,433,1106,0,449,1001,64,1,64,1002,64,2,64,109,8,21107,41,40,0,1005,1016,465,1106,0,471,4,455,1001,64,1,64,1002,64,2,64,109,6,21107,42,43,-6,1005,1016,489,4,477,1105,1,493,1001,64,1,64,1002,64,2,64,109,-26,1208,8,28,63,1005,63,513,1001,64,1,64,1105,1,515,4,499,1002,64,2,64,109,29,2105,1,-1,4,521,1001,64,1,64,1105,1,533,1002,64,2,64,109,-16,1201,-4,0,63,1008,63,23,63,1005,63,553,1105,1,559,4,539,1001,64,1,64,1002,64,2,64,109,4,21101,43,0,-3,1008,1010,41,63,1005,63,579,1106,0,585,4,565,1001,64,1,64,1002,64,2,64,109,-8,1207,-3,24,63,1005,63,605,1001,64,1,64,1106,0,607,4,591,1002,64,2,64,109,1,2102,1,-2,63,1008,63,25,63,1005,63,627,1106,0,633,4,613,1001,64,1,64,1002,64,2,64,109,4,2108,25,-7,63,1005,63,653,1001,64,1,64,1106,0,655,4,639,1002,64,2,64,109,16,21102,44,1,-8,1008,1018,44,63,1005,63,681,4,661,1001,64,1,64,1106,0,681,1002,64,2,64,109,-32,1202,9,1,63,1008,63,22,63,1005,63,703,4,687,1105,1,707,1001,64,1,64,1002,64,2,64,109,1,2107,26,9,63,1005,63,725,4,713,1105,1,729,1001,64,1,64,1002,64,2,64,109,21,1206,5,745,1001,64,1,64,1106,0,747,4,735,1002,64,2,64,109,3,1205,1,763,1001,64,1,64,1106,0,765,4,753,1002,64,2,64,109,-18,2101,0,5,63,1008,63,24,63,1005,63,785,1105,1,791,4,771,1001,64,1,64,1002,64,2,64,109,6,21102,45,1,4,1008,1011,48,63,1005,63,811,1106,0,817,4,797,1001,64,1,64,1002,64,2,64,109,5,21108,46,46,1,1005,1013,835,4,823,1106,0,839,1001,64,1,64,1002,64,2,64,109,-5,21108,47,45,8,1005,1015,855,1105,1,861,4,845,1001,64,1,64,1002,64,2,64,109,9,1206,4,875,4,867,1105,1,879,1001,64,1,64,1002,64,2,64,109,-7,2107,23,-6,63,1005,63,895,1106,0,901,4,885,1001,64,1,64,4,64,99,21101,27,0,1,21101,915,0,0,1106,0,922,21201,1,51547,1,204,1,99,109,3,1207,-2,3,63,1005,63,964,21201,-2,-1,1,21101,942,0,0,1106,0,922,22102,1,1,-1,21201,-2,-3,1,21102,1,957,0,1106,0,922,22201,1,-1,-2,1106,0,968,21202,-2,1,-2,109,-3,2105,1,0
diff --git a/aoc2019/src/day09.rs b/aoc2019/src/day09.rs
new file mode 100644
index 0000000..b1a854a
--- /dev/null
+++ b/aoc2019/src/day09.rs
@@ -0,0 +1,79 @@
+use std::fmt::Write;
+
+use aoc::err;
+use aoc::Result;
+
+use crate::intcode::{parse_memory, Intcode};
+
+const INPUT: &str = include_str!("../input/day09.txt");
+
+pub fn run() -> Result<String> {
+    let mut res = String::with_capacity(128);
+
+    let memory = parse_memory(INPUT)?;
+
+    writeln!(res, "part 1: {}", part1(memory.clone())?)?;
+    writeln!(res, "part 2: {}", part2(memory)?)?;
+
+    Ok(res)
+}
+
+fn part1(memory: Vec<i64>) -> Result<i64> {
+    let mut intcode = Intcode::with_memory(memory);
+
+    intcode.add_input(1);
+    intcode.run()?;
+    intcode
+        .get_day05_output()
+        .ok_or_else(|| err!("intcode output was empty!"))
+}
+
+fn part2(memory: Vec<i64>) -> Result<i64> {
+    let mut intcode = Intcode::with_memory(memory);
+
+    intcode.add_input(2);
+    intcode.run()?;
+    intcode
+        .get_day05_output()
+        .ok_or_else(|| err!("intcode output was empty!"))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const PROVIDED1: &str = "109,1,204,-1,1001,100,1,100,1008,100,16,101,1006,101,0,99";
+    const PROVIDED2: &str = "1102,34915192,34915192,7,4,7,99,0";
+    const PROVIDED3: &str = "104,1125899906842624,99";
+
+    #[test]
+    fn part1_provided() {
+        let memory = parse_memory(PROVIDED1).unwrap();
+        let mut intcode = Intcode::with_memory(memory.clone());
+        intcode.run().unwrap();
+        assert_eq!(intcode.output, memory, "should output a copy of itself");
+
+        let mut intcode = Intcode::new(PROVIDED2).unwrap();
+        intcode.run().unwrap();
+        assert!(
+            intcode.output[0] > 999_999_999_999_999,
+            "should be 16 digit number"
+        );
+
+        let mut intcode = Intcode::new(PROVIDED3).unwrap();
+        intcode.run().unwrap();
+        assert!(intcode.output[0] == 1_125_899_906_842_624);
+    }
+
+    #[test]
+    fn part1_real() {
+        let memory = parse_memory(INPUT).unwrap();
+        assert_eq!(part1(memory).unwrap(), 3_533_056_970);
+    }
+
+    #[test]
+    fn part2_real() {
+        let memory = parse_memory(INPUT).unwrap();
+        assert_eq!(part2(memory).unwrap(), 72_852);
+    }
+}
diff --git a/aoc2019/src/lib.rs b/aoc2019/src/lib.rs
index 88bb547..5344116 100644
--- a/aoc2019/src/lib.rs
+++ b/aoc2019/src/lib.rs
@@ -8,3 +8,4 @@ pub mod day05;
 pub mod day06;
 pub mod day07;
 pub mod day08;
+pub mod day09;
diff --git a/aoc2019/src/main.rs b/aoc2019/src/main.rs
index 0c914de..d7de35b 100644
--- a/aoc2019/src/main.rs
+++ b/aoc2019/src/main.rs
@@ -9,6 +9,7 @@ use aoc2019::day05;
 use aoc2019::day06;
 use aoc2019::day07;
 use aoc2019::day08;
+use aoc2019::day09;
 
 fn main() -> Result<()> {
     let days: &[DayFunc] = &[
@@ -20,6 +21,7 @@ fn main() -> Result<()> {
         day06::run,
         day07::run,
         day08::run,
+        day09::run,
     ];
 
     aoc::run(days)