Can you file in two states if you are in the military?

Yes, you can file in two states if you are in the military.  You may file in Iowa, from tax standpoint, your State of Legal Residency. You may also file in California, if you had non-military income and/or state income taxes withheld. 

The return filed in California be a non-resident return. 

If a military person is an Iowa resident, he or she must file an Iowa individual income tax return if:

• married and their combined income* totals more than $13,500 ($32,000 if you or your spouse is 65 or older on 12/31/14)
• single and total income* is more than $9,000 ($24,000 if 65 or older on 12/31/14)
• has income* of $5,000 or more and is claimed as a dependent on another person's Iowa return
• filing as head of household or qualifying widow(er) and total income* is more than $13,500 ($32,000 if you or your spouse is 65 or older on 12/31/14)

*does not include pay received from the federal government for military service performed by members of the armed forces, armed forces military reserve, and the national guard in an active duty status

See the following information for State Filing Rules:

https://ttlc.intuit.com/replies/3299939