I worked away from home and didn't receive reimbursement for lodging or meals. Can I use the combined irs per diem rate or do I need to figure lodging separately?

There is no combined IRS lodging rate.  There is a per diem rate for meals.  Lodging must be based only on actual costs.

The DOD publishes per diem rates for Alaska, Hawaii, etc.. It gives rates for 'Max Lodging, Local Meals, Proportioned Meals, Local Incidental and a Max Perdiem' which is the total of lodging, meals and incidentals. So are you saying that we cannot use the posted rate on our Federal Income tax return? I worked as a construction worker there for 2 months until the job was completed.