Every encounter should be complete on their own. He can't document a DX on intial eval and then every subsequent visit is assumed to be the same. Can't assume. I guess I would view this as lazy documentation
At a minimum, he should document the DX as "unchanged from April 1, 2009", then you can code from that
Here is a paste from Medicare/Trailblazer
Providers should follow these guidelines for medical record documentation when billing for psychiatry and psychology services.
The medical record should be complete and legible.
The documentation of each visit should include:
o The date.
o The reason for the visit (medically necessary).
o Appropriate history and physical exam.
o Review of lab, X-ray data and other technical services, where appropriate.
o Assessment, clinical impression.
o Plan for care (including discharge plan, if appropriate).
Past and present diagnoses should be available to the treating and/or consulting physician.
The reasons for and results of X-rays, lab tests and other technical services should be documented or included in the medical record.
Relevant health risk factors should be identified.
The patient’s progress, including response to treatment, change in treatment, change in diagnosis and patient non-compliance should be documented.
The written plan for care should include, when appropriate: treatments and medications specifying frequency and dosage; any referrals and consultations (prior to January 1, 2010); patient/family education; and specific instructions for follow-up.
The documentation should support the intensity of the patient evaluation and/or the treatment, including thought processes and the complexity of medical decision-making.
All entries to the medical record should be dated and authenticated.
The CPT/ICD-9-CM codes reported on the health insurance claim form or billing statement should reflect the documentation in the medical record.